Programming Assignment

Some common errors in Task 1

We recommend that you check your solution against the points listed here before submitting your work.

Entity-relationship diagram

• Remember to indicate key attributes.
• Lines in E-R diagram should go directly from entity rectangles to relationship diamonds - lines should not join each other. Similarly, the line from an attribute should go directly to the entity on which that attribute is defined (and should not join with other lines).
• Ensure that the cardinality of relationships is indicated correctly.
• A subclass is only necessary if the subclass has some additional attributes or relationships that the more general superclass doesn't have.

Database schema and functional dependencies

• A key must be specified for each relation.
• Relationship relations are only needed for many-to-many relationships.
• Ensure that attribute names are used consistently in your relation schemas, references and FDs.
• A functional dependency should only refer to attributes in one relation. State which relation each FD refers to.